Standing calf raises activate two muscles that run down the lower leg called the gastrocnemius and the soleus. Together they power the extension and flexion of the ankle and therefore play a key role in running and jumping. In addition, the soleus muscle delivers a host of other health benefits. For instance, it is unable to store sugar therefore, when activated it takes its fuel directly from the bloodstream lowering blood glucose and reducing excess blood sugar. Studies have found that despite its relatively small size and small range of movement the soleus muscle burns a disproportionate amount of energy, increasing metabolic rate for hours after it has been activated and it plays a key role in lowering VLDL cholesterol levels and benefiting arterial health and heart health. Plus, strong calves help you fight high-impact workout induced fatigue and make you both more powerful and more durable.